Method for accelerating a vehicle from rest

ABSTRACT

A method for accelerating a vehicle from rest. The method includes receiving a mode indication indicating a launch control mode selected; receiving a brake-on indication; controlling the engine according to a launch control strategy; determining an accelerator position; for an accelerator position greater than zero, controlling the engine to: increase open a throttle valve and control the engine to limit engine torque output; receiving a brake-off indication; controlling the engine according to the standard control strategy, controlling the engine according to the standard control strategy with the braking system having been released causing the vehicle to accelerate from rest, a first rate of acceleration from rest of the vehicle being greater than a second rate of acceleration from rest of the vehicle for corresponding changes in accelerator position, the first rate corresponding to accelerating from rest after controlling the engine according to the standard and launch control strategies.

CROS S-REFERENCE

The present application claims priority to U.S. Provisional PatentApplication No. 63/143,095, entitled “Method for Accelerating a Vehiclefrom Rest,” filed Jan. 29, 2021, the entirety of which is incorporatedherein by reference.

FIELD OF THE TECHNOLOGY

The present technology relates to controlling an engine of a vehicle,and more specifically to methods for accelerating a vehicle from rest.

BACKGROUND

For vehicles having turbo-charged internal combustion engines, such asthose used in snowmobiles and all-terrain vehicles (ATVs), theefficiency of the combustion process can be increased by compressing theair entering the engine. This can be accomplished using a turbochargerconnected to the air intake and exhaust systems of the snowmobiles. Thecompression of the air by the turbocharger may be of particularimportance when the internal combustion engine is operated inenvironments where atmospheric pressure is low or when the air getsthinner, such as when the engine is operated at high altitudes.

When accelerating the vehicle from rest, however, there is a delay inthe efficiency boost from the turbocharger due to the time it takes forthe turbocharger to run at full capacity (referred to as “spooling-up”).The spooling-up process may even, in some cases, decrease air flow tothe engine, slowing the initial acceleration (referred to as“turbo-lag”). In some cases, the turbocharger could be bypassed duringinitial acceleration in order to avoid turbo-lag, but in such cases anybenefit of the turbocharger would be delayed until the turbocharger waseventually spooled-up.

There is thus a need for methods or systems for accelerating from restfor turbo-charged engines that could allow for benefitting fromturbocharger boost while overcoming some of the previously knowndisadvantages of utilizing the turbocharger during initial acceleration.

SUMMARY

It is an object of the present technology to ameliorate at least some ofthe inconveniences present in the prior art.

According to one aspect of the present technology, there is providedmethods and systems for accelerating a turbo-charged vehicle from rest.Specifically, the present embodiment is described in reference to asnowmobile and an ATV. The method includes, upon selection of a “launchcontrol” mode to aid in initial acceleration, increasing engine speedand opening a throttle valve while the vehicle is still at rest. Byopening the throttle and increasing the engine speed (revving up theengine), air flow through the engine and also the turbocharger isincreased. As such, the turbocharger can spool-up prior to initialacceleration (acceleration from rest) of the vehicle. This allows forfaster acceleration from rest, as boost from the turbocharger isavailable for all of the initial acceleration, with generally no timelost to spooling up and generally without loss of acceleration powerfrom lagging in the turbocharger. In order to avoid the vehicle fromprematurely accelerating when the throttle is open, by engaging atransmission and/or overwhelming the brakes for example, engine speedand torque are limited while the engine is idling at increased enginespeed and the throttle is open. Engine speed and torque limiting areachieved by causing inefficient ignition which is produced by adjustingthe ignition angle to delay combustion ignition in one or morecylinders. Engine speed and torque limiting can additionally oralternatively be achieved by deactivating one or more cylinders bypreventing ignition and fuel injection periodically in a given cylinder.

According to an aspect of the present technology, there is provided amethod for accelerating a vehicle from rest. The method includescontrolling, by a controller, an engine of the vehicle according to afirst control strategy; receiving, by the controller, a mode indicationindicating that an operator of the vehicle has selected a launch controlmode for accelerating the vehicle; receiving, by the controller, abrake-on indication indicating that a braking system of the vehicle hasbeen activated; in response to receiving at least the mode indicationand the brake-on indication, controlling the engine, by the controller,according to a second control strategy; while controlling the engineaccording to the second control strategy, determining, by thecontroller, an accelerator position of an accelerator of the vehicle; inresponse to the accelerator position being greater than zero,controlling, by the controller, the engine to: increase, according tothe accelerator position, an opening of a throttle valve of the engine,and control operational conditions of the engine to limit engine torqueoutput; while controlling the engine according to the second controlstrategy, receiving, by the controller, a brake-off indicationindicating that the braking system has been released; and in response toreceiving the brake-off indication, controlling the engine, by thecontroller, according to the first control strategy, controlling theengine according to the first control strategy with the braking systemhaving been released causing the vehicle to accelerate from rest, afirst rate of acceleration from rest of the vehicle being greater than asecond rate of acceleration from rest of the vehicle for correspondingchanges in accelerator position, the first rate of accelerationcorresponding to the vehicle accelerating from rest after sequentiallycontrolling the engine according to the first and second controlstrategies; the second rate of acceleration corresponding to the vehicleaccelerating from rest by controlling the engine according to the firstcontrol strategy without previously controlling the engine according tothe second control strategy.

In some embodiments, controlling the engine according to the secondcontrol strategy includes: increasing a speed of the engine, andlimiting a torque output of the engine.

In some embodiments, controlling the engine according to the firstcontrol strategy comprises controlling a turbocharged engine of thevehicle according to standard operational parameters.

In some embodiments, the method of further includes determining, by thecontroller, that a speed of the engine has surpassed a threshold enginespeed; and wherein the controller controls the engine according to thesecond control strategy in response to receiving the mode indication andthe brake-on indication, and determining that the engine speed hassurpassed a threshold engine speed.

In some embodiments, the method further includes prior to receiving themode indication, determining, by the controller, that each of aplurality of initial mode conditions have been met; and in response tothe plurality of initial mode conditions being met, enabling a modeinput by the controller, the mode indication being sent to thecontroller from the mode input upon selection of the launch control modeby the operator via the mode input.

In some embodiments, the method further includes while controlling theengine according to the second control strategy: determining, by thecontroller, that at least one deactivation condition has been met; andin response to the at least one deactivation condition being met,returning to a standard operation mode whereby the vehicle is operatedaccording to the first control strategy.

In some embodiments, determining that the at least one deactivationcondition has been met includes determining that a time limit ofcontrolling the engine according to the second control strategy has beenreached.

In some embodiments, the method further includes subsequent to receivingthe mode indication and prior to receiving the brake-off indication:determining, by the controller, that at least one deactivation conditionhas been met; and in response to the at least one deactivation conditionbeing met, returning to a standard operation mode whereby the vehicle isoperated according to the first control strategy.

In some embodiments, controlling operational conditions of the engine tolimit engine torque output comprises at least one of: delayingcombustion ignition; and deactivating at least one cylinder.

In some embodiments, in response to increasing the opening of thethrottle valve according to the accelerator position, air flow increasesthrough the engine.

In some embodiments, in response to controlling the engine according tothe first and second control strategies, a speed of rotation of aturbocharger of the vehicle increases.

In some embodiments, a first speed of rotation of a turbocharger of thevehicle upon acceleration from rest is greater than a second speed ofrotation of the turbocharger upon acceleration from rest; the firstspeed of rotation corresponds to the vehicle accelerating from restafter sequentially controlling the engine according to the first andsecond control strategies; and the second speed of rotation correspondsto the vehicle accelerating from rest by controlling the engineaccording to the first control strategy without previously controllingthe engine according to the second control strategy.

In some embodiments, in response to receiving the mode indication andprior to controlling the engine according to the second strategy,controlling the engine to increase engine speed.

In some embodiments, the method further includes subsequent to receivingthe mode indication and prior to controlling the engine according to thefirst strategy: determining, by the controller, that at least onedeactivation condition has been met; and in response to the at least onedeactivation condition being met, returning to a standard operation modewhereby the vehicle is operated according to the first control strategy.

In some embodiments, determining that the at least one deactivationcondition has been met includes determining that a time limit ofincreased engine speed has been reached.

According to another aspect of the present technology, there is provideda vehicle including a frame; at least one seat connected to the frame;an engine supported by the frame; a turbocharger operatively connectedto the engine; a controller communicatively connected to the engine; andan accelerator communicatively connected to the controller, thecontroller being configured to perform the method of any of the aboveembodiments.

According to yet another aspect of the present technology, there isprovided a vehicle including a frame; at least two ground engagingmembers connected to the frame; a braking system operatively connectedto at least one of the at least two ground engaging members; at leastone seat connected to the frame; an engine supported by the frame; aturbocharger operatively connected to the engine; a controllercommunicatively connected to the engine; and an acceleratorcommunicatively connected to the controller, the controller beingconfigured to perform the steps of: controlling, by a controller, anengine of the vehicle according to a first control strategy; receiving,by the controller, a mode indication indicating that an operator of thevehicle has selected a launch control mode for accelerating the vehicle;receiving, by the controller, a brake-on indication indicating that abraking system of the vehicle has been activated; in response toreceiving the mode indication and the brake-on indication, controllingthe engine, by the controller, according to a second control strategy;while controlling the engine according to the second control strategy,determining, by the controller, an accelerator position of anaccelerator of the vehicle; in response to the accelerator positionbeing greater than zero, controlling, by the controller, the engine to:increase, according to the accelerator position, an opening of athrottle valve of the engine, and control operational conditions of theengine to limit engine torque output; while controlling the engineaccording to the second control strategy, receiving, by the controller,a brake-off indication indicating that the braking system has beenreleased; and in response to receiving the brake-off indication,controlling the engine, by the controller, according to the firstcontrol strategy, controlling the engine according to the first controlstrategy with the braking system having been released causing thevehicle to accelerate from rest, a first rate of acceleration from restof the vehicle being greater than a second rate of acceleration fromrest of the vehicle for corresponding changes in accelerator position,the first rate of acceleration corresponding to the vehicle acceleratingfrom rest after sequentially controlling the engine according to thefirst and second control strategies; the second rate of accelerationcorresponding to the vehicle accelerating from rest by controlling theengine according to the first control strategy without previouslycontrolling the engine according to the second control strategy.

In some embodiments, the vehicle further includes a mode inputcommunicatively connected to the controller; and wherein the controlleris further configured to perform the steps of: prior to receiving themode indication, determining, by the controller, that each of aplurality of initial mode conditions have been met, and in response tothe plurality of initial mode conditions being met, enabling the modeinput by the controller to allow the operator to select the launchcontrol mode.

In some embodiments, the vehicle is a snowmobile; the at least twoground engaging elements include: two skis connected to the frame, andan endless track disposed rearward of the two skis; the at least oneseat is at least one straddle-seat; and the accelerator is anaccelerator lever.

In some embodiments, the vehicle is an all-terrain vehicle (ATV); the atleast two ground engaging elements include at least two wheels; the atleast one seat is at least one straddle-seat; and the accelerator is anaccelerator lever.

According to yet another aspect of the present technology, there isprovided a method for accelerating a vehicle from rest. The methodincludes controlling, by a controller, an engine of the vehicle, theengine having a first mode and a second mode: the first mode controllingthe engine speed from a first idle speed to a first maximum engine speedwith respect to a corresponding idle accelerator position and a maximumaccelerator position; the second mode controlling the engine speed froma second idle speed to a second maximum engine speed with respect to thecorresponding idle acceleration position and the maximum accelerationposition, the second maximum engine speed being less than the firstmaximum engine speed, receiving, by the controller, a mode indicationindicating that an operator of the vehicle has selected a launch controlmode for accelerating the vehicle; receiving, by the controller, abrake-on indication indicating that a braking system of the vehicle hasbeen activated; in response to receiving the mode indication and thebrake-on indication, controlling the engine, by the controller,according to the second mode; while controlling the engine according tothe second mode, receiving, by the controller, a brake-off indicationindicating that the braking system has been released; and in response toreceiving the brake-off indication, controlling the engine, by thecontroller, according to the first mode, controlling the engineaccording to the first mode with the braking system having been releasedcausing the vehicle to accelerate from rest.

For purposes of this application, terms related to spatial orientationsuch as forwardly, rearward, upwardly, downwardly, left, and right, areas they would normally be understood by an operator of a vehicle sittingthereon in a normal riding position. Terms related to spatialorientation when describing or referring to components or sub-assembliesof the vehicle, separately from the vehicle, should be understood asthey would be understood when these components or sub-assemblies aremounted to the vehicle, unless specified otherwise in this application.

Embodiments of the present technology each have at least one of theabove-mentioned object and/or aspects, but do not necessarily have allof them. It should be understood that some aspects of the presenttechnology that have resulted from attempting to attain theabove-mentioned object may not satisfy this object and/or may satisfyother objects not specifically recited herein. The explanations providedabove regarding the above terms take precedence over explanations ofthese terms that may be found in any one of the documents incorporatedherein by reference.

Additional and/or alternative features, aspects and advantages ofembodiments of the present technology will become apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present technology, as well as otheraspects and further features thereof, reference is made to the followingdescription which is to be used in conjunction with the accompanyingdrawings, where:

FIG. 1 is a left side elevation view of a snowmobile;

FIG. 2 is a top, rear, right side perspective view of an engine, airintake system and exhaust system of the snowmobile of FIG. 1 ;

FIG. 3 is a front elevation view of the engine, air intake system andexhaust system of FIG. 2 ;

FIG. 4A is a cross-sectional view of the engine and some portions of theair intake system and the exhaust system of FIG. 2 ;

FIG. 4B is a perspective view of a throttle system of the snowmobile ofFIG. 1 ;

FIG. 5 is a flowchart illustrating one non-limiting embodiment forcontrolling the snowmobile of FIG. 1 to accelerate from rest;

FIG. 6 is a graph depicting engine speed, accelerator position, andignition angle during a portion of the control of the snowmobile set outin FIG. 5 ;

FIG. 7 is a flowchart depicting the control of the snowmobile set out inFIG. 5 in the form of a method;

FIG. 8 is a right side elevation view of an all-terrain vehicle (ATV);and

FIG. 9 is a top plan view of the ATV of FIG. 8 .

It should be noted that the Figures may not be drawn to scale, exceptwhere otherwise noted.

DETAILED DESCRIPTION

The present technology is described herein with respect to a snowmobile10 having an internal combustion engine and two skis, and further withrespect to an all-terrain vehicle (ATV) with an internal combustionengine and four wheels. However, it is contemplated that some aspects ofthe present technology may apply to other types of vehicles such as, butnot limited to, snowmobiles with a single ski, road vehicles having two,three, or four wheels, off-road vehicles, all-terrain vehicles with moreor fewer wheels, and side-by-side vehicles.

With reference to FIGS. 1 and 2 , a snowmobile 10 according to thepresent technology will be described. The snowmobile 10 includes aforward end 12 and a rearward end 14. The snowmobile 10 includes avehicle body in the form of a frame or chassis 16 which includes atunnel 18, an engine cradle portion 20, a front suspension module 22 andan upper structure 24.

An internal combustion engine 26 is carried in an engine compartmentdefined in part by the engine cradle portion 20 of the frame 16. A fueltank 28, supported above the tunnel 18, supplies fuel to the engine 26for its operation. The engine 26 receives air from an air intake system100. The engine 26 and the air intake system 100 are described in moredetail below.

An endless drive track 30 is positioned at the rear end 14 of thesnowmobile 10. The drive track 30 is disposed generally under the tunnel18, and is operatively connected to the engine 26 through a continuouslyvariable transmission (CVT) 128 (shown schematically). The endless drivetrack 30 is driven to run about a rear suspension assembly 32operatively connected to the tunnel 18 for propulsion of the snowmobile10. The endless drive track 30 has a plurality of lugs 31 extending froman outer surface thereof to provide traction to the track 30.

The rear suspension assembly 32 includes drive sprockets 34, idlerwheels 36 and a pair of slide rails 38 in sliding contact with theendless drive track 30. The drive sprockets 34 are mounted on an axle 35and define a sprocket axis 34 a. The axle 35 is operatively connected toa crankshaft 126 (FIG. 3 ) of the engine 26 via the CVT 128. The sliderails 38 are attached to the tunnel 18 by front and rear suspension arms40 and shock absorbers 42. It is contemplated that the snowmobile 10could be provided with a different version of a rear suspension assemblythan the one shown herein.

At the rear end of the snowmobile 10, a snow flap 94 extends downwardfrom the rear end of the tunnel 18. The snow flap 94 protects againstdirt and snow that can be projected upward from the drive track 30 whenthe snowmobile 10 is being propelled by the moving drive track 30. It iscontemplated that the snow flap 94 could be omitted.

A straddle seat 60 for receiving an operator of the snowmobile 10 ispositioned atop the fuel tank 28. A fuel tank filler opening covered bya cap 92 is disposed on the upper surface of the fuel tank 28 in frontof the seat 60. It is contemplated that the fuel tank filler openingcould be disposed elsewhere on the fuel tank 28. The seat 60 is adaptedto accommodate the operator, also referred to as a driver, of thesnowmobile 10. The seat 60 could also be configured to accommodate apassenger. A footrest 64 is positioned on each side of the snowmobile 10below the seat 60 to accommodate the driver's feet.

The snowmobile 10 includes an ignition key base 65 mounted to thesnowmobile 10 forward of the seat 60. It is contemplated that parts ofthe base 65 could be integral with the top surface of the snowmobile 10.The base 65 is adapted to receive an ignition key 67 (illustrated asengaged with the base 65 in FIG. 1 ). The key 67 serves, at least inpart, as an anti-theft system as the snowmobile 10 is prevented fromstarting when the ignition key 67 is not engaged with the base 65. Incases where the snowmobile 10 is to be operated by a less experiencedoperator, by a riding student or a renter for example, the key 67 couldbe replaced with a learner key (not shown) which would limit certainoperational characteristics. For example, the learner key could limitaspects including, but not limited to: snowmobile top speed andacceleration. In some embodiments, the key 67 could be equipped with asecurity system such as, for example, Bombardier Recreational Product'sDigitally Encoded Security System (DESS™). It is also contemplated thatdifferent anti-theft and/or security systems could be implemented by thesnowmobile 10 and/or the key 67.

At the front end 12 of the snowmobile 10, fairings 66 enclose the engine26 and the CVT 128, thereby providing an external shell that not onlyprotects the engine 26 and the CVT 128, but can also make the snowmobile10 more aesthetically pleasing. The fairings 66 include a hood 68 andone or more side panels which can be opened to allow access to theengine 26. A windshield 69 connected to the fairings 66 acts as a windscreen to lessen the force of the air on the rider while the snowmobile10 is moving. It is contemplated that the windshield 69 could beconnected directly to a handlebar 84.

Two skis 70 positioned at the forward end 12 of the snowmobile 10 areattached to the front suspension module 22 of the frame 16 through afront suspension assembly 72. The front suspension module 22 isconnected to the front end of the engine cradle portion 20. The frontsuspension assembly 72 includes ski legs 74, supporting arms 76 and balljoints (not shown) for operatively connecting to the respective ski leg74, supporting arms 76 and a steering column 82 (schematicallyillustrated).

A steering assembly 80, including the steering column 82 and a handlebar84, is provided generally forward of the seat 60. The steering column 82is rotatably connected to the frame 16. The lower end of the steeringcolumn 82 is connected to the ski legs 74 via steering rods (not shown).The handlebar 84 is attached to the upper end of the steering column 82.The handlebar 84 is positioned in front of the seat 60. The handlebar 84is used to rotate the steering column 82, and thereby the skis 70, inorder to steer the snowmobile 10. An accelerator lever 86 (also referredto as an accelerator, throttle lever, or throttle operator) in the formof a thumb-actuated lever is mounted to the right side of the handlebar84. Other types of accelerator or throttle operators, such as afinger-actuated throttle lever and a twist grip, are also contemplated.A brake actuator 88, in the form of a hand brake lever 88, is providedon the left side of the handlebar 84 for controlling a braking system 89of the snowmobile 10 (shown schematically in FIG. 1 ). In the case ofimplementation of the present methods or systems with differentvehicles, for example all-terrain vehicles (ATVs) and/or side-by-sidevehicles (SSVs), it is contemplated that the brake actuator could be inthe form of a foot-actuated brake (i.e. a brake pedal).

A mode input 184, specifically a mode selection button 184, is disposedin a display cluster 185 forward of the handlebar 84. In someembodiments, it is contemplated that the button 184 could be mounted tothe left side of the handlebar 84. By pressing on the mode selectionbutton 184, the operator can choose between different driving modes ofthe snowmobile 10, in the present embodiment, between sport, standard,and economy modes. Additional or alternative modes are alsocontemplated. As will be described in more detail below, a launchcontrol mode can also be chosen via the mode selection button 184 to aidin accelerating the snowmobile 10 from rest. The launch control mode isselected by first selecting the sport mode by repeatedly pushing themode selection button until the sport mode has been selected, and thenholding the button 184 down until the launch control mode has beenfurther selected. It is contemplated that the mode input 184 could beimplemented in different manners, including for example via a touchscreen or a dial. It is also contemplated that the snowmobile 10 couldinclude a mode input button dedicated for selecting the launch controlmode. It is further contemplated that the launch control mode could be adefault setting as part of the sport mode. In some non-limitingembodiments, the launch control mode could instead be selected withoutfirst selecting sport mode.

The snowmobile 10 includes other components such as an interactive touchscreen and the like. In some embodiments, selection of the differentdrive modes and the launch control mode described further below, couldbe done using the interactive touch screen or a handlebar mounted buttonin some embodiments.

With additional reference to FIGS. 3 and 4A, the engine 26 and the airintake system 100 will be described in more detail. Air from theatmosphere flows through side apertures 93 defined in an upper portion25 of the upper structure 24 of the chassis 16 (FIG. 2 ). The air thenflows into a secondary airbox 110. The secondary airbox 110 is disposedabove the front suspension module 22. A conduit 117 (FIG. 3 ) fluidlyconnects the secondary airbox 110 to a turbocharger 170, specifically toan inlet 173 of an air compressor 172 (FIG. 3 ) of the turbocharger 170disposed on the front side of the engine 26. It is contemplated that thesecondary airbox 110 could be omitted and that air from the atmospherecould directly enter into the inlet 173 without going through thesecondary airbox 110.

Air from the atmosphere, passing through the secondary airbox 110 andinto the air compressor 172 via the conduit 117 and inlet 173, iscompressed by the air compressor 172. The compressed air then flows outof the air compressor 172 through an outlet 174, into a conduit 115 andinto an intercooler 113. The intercooler 113 is fluidly connected to aprimary airbox 120 via the conduit 118 (FIG. 2 ) which is in turnconnected to the engine 26 via air outlets 123 of the primary airbox120. The primary airbox 120 includes an intake air temperature sensor121 (shown schematically in FIG. 4A) for measuring the temperature ofair flowing into the engine 26. In some embodiments, the airbox 120could additionally or alternatively include an air pressure sensor.

With additional reference to FIG. 4B, the engine 26 and the turbocharger170 are described in further detail. The engine 26 is an inline,three-cylinder, four-stroke, internal combustion engine. The cylindersof the engine 26 are oriented with their cylindrical axes disposedvertically. It is contemplated that the engine 26 could be configureddifferently. For example, the engine 26 could have more or fewercylinders, and the cylinders could be arranged in a V-configurationinstead of in-line. It is contemplated that in some embodiments theengine 26 could be a two-stroke internal combustion engine, a carburetedengine, or any other suitable engine capable of propelling thesnowmobile 10.

The snowmobile 10 includes an engine control unit (ECU) 155, shown inFIG. 4B and schematically in FIG. 4A, for communicating with andcontrolling the engine 26. The ECU 155 includes at least anon-transitory computer readable medium (not shown) and a processor (notshown). The processor of the ECU 155 is configured to perform a numberof operations including speed and torque limiting operations describedbelow with respect to methods for accelerating the snowmobile 10 fromrest. It is contemplated that the functions of the ECU 155 could besplit between multiple ECUs.

An engine speed sensor 157 and an engine temperature sensor 159 (shownschematically) are disposed in the engine 26. The engine speed sensor157 senses the rotational speed (RPM) of the engine 26. The enginetemperature sensor 159 measures the temperature of engine coolant of theengine 26. The engine sensors 157, 159 are communicatively connected tothe ECU 155. In some embodiments, the engine sensors 157, 159 could beimplemented as a unified engine sensing unit. It is contemplated thatadditional or alternative sensors could be used to monitor the engine26.

As shown in FIGS. 1, 2, and 4A, the engine 26 receives air from the airintake system 100, specifically from the primary airbox 120, via engineair inlets 27 defined in the rear portion of each cylinder of the engine26. Each air inlet 27 is connected to a single throttle body 37 of theair intake system 100; a throttle system assembly 137 is illustrated inisolation in FIG. 4B . The throttle body 37 has a throttle valve 39which rotates to regulate the amount of air flowing through the throttlebody 37 into the corresponding cylinder of the engine 26. A throttlevalve actuator 139 is operatively connected to the throttle valve 39 tochange the position of the throttle valve 39 and thereby adjust theopening of the throttle valve 39 with operation of the accelerator lever86 on the handlebar 84. The accelerator lever 86 is movable between a 0%position (where the throttle valve 39 is closed), a 100% position (wherethe throttle valve 39 is at its most open position), as well as to aplurality of positions between the 0% and the 100% positions (where thethrottle valve 39 is partially opened to a position based at least inpart on the lever position).

In the present embodiment, the throttle system assembly 137 is a hybridmechanical cable and drive-by-wire system (see FIG. 4B), although thisis simply one non-limiting embodiment. The position and the movement ofthe throttle valve 39 is monitored by a throttle valve position sensor187 operatively connected to the throttle valve 39. The actuator 139changes the position of the throttle valve 39 based on input signalsreceived from an electronic control module 189 which in turn receivesinputs signals from a position sensor 183 associated with theaccelerator lever 86 on the handlebars 84.

The engine 26 receives fuel from the fuel tank 28 via injectors 41 shownin at least FIG. 4A. The fuel-air mixture in each of the cylinders ofthe engine 26 is ignited by an ignition system including spark plugs 43(best seen in FIG. 4A). Engine output power, torque and engine speed aredetermined in part by throttle opening and in part by the ignitiontiming, and also by various characteristics of the fuel-air mixture suchas its composition, temperature, pressure and the like. Control ofengine ignition will be described in more detail below.

Exhaust gases resulting from the combustion events in the cylinders areexpelled from the engine 26 via an exhaust system 99. An exhaust outlet29 is defined in the front portion of each cylinder of the engine 26,each cylinder has an exhaust outlet 29 and an exhaust valve 129. Theexhaust outlets 29 are fluidly connected to an exhaust manifold 33 whichis fluidly connected to the turbocharger 170.

The turbocharger 170 is operatively connected to the engine 26 as ismentioned above. The turbocharger 170 compresses air and feeds it to theengine 26. The turbocharger 170 includes the air compressor 172 and anexhaust turbine 176 (FIG. 3 ). The air compressor 172 includes acompressor wheel 174 and is part of the air intake system 100 (describedabove). Intake air flowing past the rotating compressor wheel 172 iscompressed thereby. The rotation of the compressor wheel 172 is poweredby a turbine wheel of the exhaust turbine 176. The turbine wheel isrotated by exhaust gases expelled from the engine 26 and directed toflow over the blades of the turbine wheel.

The exhaust system 99 further includes a muffler 97 for removing exhaustgas from the snowmobile 10. The muffler 97 is fluidly connected to theturbocharger 170, specifically an outlet of the compressor, by anexhaust collector 95 (FIG. 3 ). It is contemplated that differentarrangements could be employed to connect the muffler 97 to the exhaustcollector 95.

As is illustrated schematically in FIG. 4A, the snowmobile 10 furtherincludes a controller 150. The controller 150 includes at least anon-transitory computer readable medium (not shown) and a processor (notshown). The processor of the controller 150 is configured to perform anumber of operations including methods described below for acceleratingthe snowmobile 10 from rest (the above mentioned launch control mode).It is contemplated that the functions of the controller 150 could besplit between multiple controllers. It is also contemplated that the ECU155 could perform the processes and methods of the controller 150 of theembodiments described herein, and in such cases the controller 150 couldbe excluded.

The controller 150 is operatively connected to the engine control unit(ECU) 155 of the snowmobile 10 (shown schematically). The ECU 155 is inturn operatively connected to the engine 26, such that the controller150 can monitor and control engine operations via the ECU 155. It iscontemplated that the controller 150 operations described herein couldbe performed by the ECU 155 in some embodiments. As is mentioned above,the ECU 155 is communicatively connected to the engine sensors 157, 159for receiving information therefrom with respect to engine speed andtemperature respectively. The controller 150 is thus connected to theengine sensors 157, 159 via the ECU 155. It is contemplated that thecontroller 150 could be communicatively connected to alternative and/oradditional sensors via the ECU 155 in some embodiments. The controller150 and the ECU 155 are also communicatively connected to the mode inputbutton 184, in order to control the engine 26 and the snowmobile 10according to the mode selected by the operator.

The controller 150 is further operatively and communicatively connectedto the intake air temperature sensor 121 for monitoring the temperatureof air entering the engine 26 and the throttle valve position sensor 187for determining the position of the throttle valve 39, a rate of openingof the throttle valve 39, the actuator position sensor 183, or both. Thecontroller 150 is further communicatively connected to the acceleratorlever position sensor 183 for sensing the accelerator lever position.The controller 150 is also communicatively connected to the brake lever88 and the braking system 89 for sensing brake activation status of thebraking system 89.

Depending on the embodiment, the controller 150 could be connected tovarious alternative and/or additional sensors for monitoring componentsor characteristics of the engine 26 and/or the snowmobile 10. Forexample, the controller 150 could be communicatively connected to anexhaust pipe temperature sensor to monitor the temperature of an exhaustpipe and/or the temperature of exhaust exiting the engine 26.

Accelerating the snowmobile 10 from rest, using an operating modereferred to herein as the launch control mode, in accordance withnon-limiting embodiments of the present technology will now be describedin more detail with reference to FIGS. 5 and 6 . An overview of stepstaken by the operator and operations performed by the controller 150and/or the snowmobile 10 according to the launch control mode isillustrated by a flowchart 200 presented in FIG. 5 .

The controller 150 first determines if the selection of launch controlmode should be made available to the operator of the snowmobile 10 atoperation 210. The determination is made by the controller 150 byconfirming that one or more activation conditions, also referred to asinitial mode conditions, have been met. Confirmation by the controller150 that the activation conditions have been met is done at least uponignition of the snowmobile 10, as well as in response to the snowmobile10 subsequently coming to rest. The controller 150 further verifies thatactivation conditions have been met at regular spaced intervals, forexample every 10 milliseconds, while the snowmobile 10 is running. Insome embodiments, the regularly spaced time intervals could be greateror lesser than 10 ms. It is also contemplated that the controller 150could verify the activation conditions in response to the snowmobile 10is put into sport mode or another selected mode.

The activation conditions to be met in order to make the launch controlmode available for the operator to activate include the followingconditions, but in different embodiments the controller 150 may consideronly some of these or additional and/or alternative conditions. First,the snowmobile 10 should be in a forward gear, with the engine 26running. The snowmobile 10 should be in the sport mode, as chosenthrough the mode input button 184. The snowmobile 10 should have a speedof 0 km/h (0 mph), such that the snowmobile 10 is at rest. The speed ofthe snowmobile 10 is determined by a speed sensor (not shown). Thetemperature of the engine 26, as determined by the engine temperaturesensor 159, should be between a minimum and a maximum mode-acceptableengine temperature. The temperature of intake air entering the engine26, as determined by the intake air temperature sensor 121, should alsobe between a minimum and a maximum mode-acceptable air temperature. Theexact minimum and maximum temperatures are stored tocomputer-implemented storage connected to the controller 150, althoughit is contemplated that the minimum and maximum engine temperaturescould be calculated by the controller 150 directly. The controller 150also determines that the key 67 connected to the snowmobile 10 is a keyprogrammed to allow the launch control mode, e.g. is not a learner key.The accelerator lever position should be at 0%, where the operator hasnot applied any throttle and the snowmobile 10 is idling. Further, amaximum number of previous launch control mode starts, for apredetermined time period, should not have been surpassed. In someembodiments, for instance, there may be a limit on the number of timesacceleration from rest using the launch control mode may be permittedfor a particular time frame of the snowmobile 10, and the nextacceleration from rest using the launch control mode may not be alloweduntil the snowmobile 10 has first been shut down.

As part of the activation or initial mode conditions, the controller 150also determines that the snowmobile 10 has no pre-determinedunacceptable faults. Specifically, while one or more faults or errors incomponents of snowmobile 10 may be sensed and/or identified by thecontroller 150 during determination of the activation conditions, it iscontemplated that some “faults” detected may be acceptable and shouldnot impede implementation of the launch control mode. There are somefaults, however, that are determined to be incompatible withimplementation of the launch control mode and thus are labeled“unacceptable”. As one non-limiting example of such an unacceptablefault, the controller 150 may not make the launch control mode availableif it is determined that the position sensor 183 for sensing theposition of the accelerator lever 186 is dysfunctional or notcommunicating with the controller 150. As one other non-limiting exampleof such an unacceptable fault, the controller 150 may not make thelaunch control mode available if it is determined that the valveposition sensor 187 is dysfunctional or not communicating with thecontroller 150.

If the activation conditions (initial mode conditions) are met, thecontroller 150 enables the mode input 184 to allow the operator toselect the launch control mode at operation 220.

In response to the operator selecting the launch control mode via themode input 184, the controller 150 activates (or “arms”) the launchcontrol mode to control the snowmobile 10 in operation 230. Prior toselection of the launch control mode, the snowmobile 10 and the engine26 are controlled according to a standard control strategy. Controlstrategies generally vary between different embodiments of the engine 26and a person skilled in the art would understand adaptations necessaryfor a particular embodiment. For example, one such strategy couldinclude sensing a throttle lever angle, determining a torque requestbased on this lever angle, and controlling a throttle valve opening,fuel injection amount and ignition timing to achieve the requestedtorque. Control strategies are generally performed within a repeatingloop. Once the operator has chosen the launch control mode, thecontroller 150 controls the snowmobile 10 and the engine 26 according toa launch control strategy, different from the standard control strategy,which provides instructions for the following operations.

The controller 150, in conjunction with the ECU 155, causes the engine26 to increase engine speed (increase idle) in response to the selectionof the launch control mode. The idle speed is increased up to a maximumof about 1800 RPM, although it is contemplated that the maximum idlespeed could vary. The idle increase serves as an auditory indication tothe operator that the launch control mode has been activated. In someembodiments, the controller 150/ECU 155 may not increase the enginespeed (idle). In some embodiments, a different auditory indication couldbe included, for example a tone being played when the launch controlmode is selected.

In response to the operator subsequently activating the braking system89 via the brake lever 88, the controller 150 then applies an enginespeed limit to the engine 26 of approximately 3200 RPM at operation 240.If the operator has previously activated the braking system 89, thecontroller 150 could perform the operation 240 immediately followingcompletion of operation 230. The exact speed to which the engine 26 islimited could vary, depending on the particular embodiment of the engine26 for example, but the speed is generally chosen to be less than anengagement speed of the CVT 128 to prevent forward movement of thesnowmobile 10. In the present embodiment, the engagement speed of theCVT 128 is approximately 3500 RPM, but this could vary depending indifferent embodiments of snowmobiles, engines, and/or CVTs.

If, subsequent to applying the engine speed limit of approximately 3200RPM at operation 240 and prior to completing any subsequent operations,the controller 150 determines that the braking system 89 has beendeactivated, the engine speed is decreased to its previous high idlespeed (up to 1800 RPM) if the engine speed had subsequently increased,and the engine speed limit previously applied is removed. The launchcontrol mode remains active, and the controller 150 once again appliesthe engine speed limit in response to the operator subsequentlyactivating the braking system 89.

In response to the operator moving the accelerator lever 86 to a greaterthan 0% position, the controller 150 then causes the throttle valve 39to open according to the accelerator lever 86 position at operation 250,and the standard control strategy is followed until the engine speedapproximately reaches the applied engine speed limit. Once the enginespeed reaches the applied engine speed limit, the controller 150controls the throttle valve position, fuel injection and ignition timingby the launch control strategy that limits the torque produced whichprevents the engine speed from going beyond the engine speed limitapplied at operation 240, but increase the air flowing through theengine 26 as will be discussed further below. It should be noted thatthe operations 240 and 250 could be combined into one operation in atleast some embodiments. It is contemplated that a different controlstrategy could be used as soon as the launch mode is activated inoperation 240 regardless of the actual engine speed.

By opening the throttle valve 39, air flow through the engine 26, aswell as the turbocharger 170, increases. Increasing air flow through theturbocharger 170, while the snowmobile 10 remains at rest, allows theturbocharger 170 to spool-up and be fully prepared to supplyturbocharger boost during initial acceleration from rest. In order toavoid engagement of the CVT 128 and the snowmobile 10 overcoming thebraking system 89 (and accelerating prematurely) due to increasingtorque and speed following opening the throttle valve 39, the controller150 applies a torque limiting process.

Controlling the engine 26 to limit torque and engine speed, whileopening the throttle valve 39, is managed by the controller 150 asfollows. As the engine speed increases beyond or approachesapproximately 3200 RPM and approaches an engagement speed for the CVT128, the controller 150 causes a change in the ignition timing for thecylinders such that the engine 26 is firing inefficiently by delayingcombustion in the cylinders. Specifically, as is illustrated in thegraph 290 of FIG. 6 , the ignition angle is set to approximately −20degrees from the top dead center (TDC) position for each piston, suchthat the spark plugs 43 are set to ignite the fuel-air mixture when thecorresponding piston is at −20 degrees from the TDC position (20 degreespast the TDC position). As the standard ignition timing is to fireapproximately 25 degrees from the TDC position, the force produced byeach combustion cycle is reduced. It is noted that the same air flowthrough the engine 26 is maintained as when the engine 26 is running ina standard manner, such that the exhaust gas flowing toward theturbocharger 170 continues generally unchanged in volume.

In some cases, the torque limiting process described above may not besufficient to limit engine speed or torque, for instance when thethrottle valve 39 is fully open (the accelerator position is 100%). Insuch a case, the controller 150 further acts to limit engine speed andtorque by deactivating one or more of the cylinders of the engine 26.When deactivating a cylinder, the piston continues to cycle, but thefuel injectors 41,45 do not inject fuel and the spark plugs 43 do notfire. When deactivating more than one cylinder, different cylinders aredeactivated during different cycles, but different approaches arecontemplated. For instance, the pattern of activation/deactivation ofcylinders could be chosen to manage vibration and heating effects in theengine 26. As was the case when delaying ignition, air flow continuesthrough the engine 26, aiding to spool up the turbocharger 170.

Having increased the throttle valve opening in operation 250 and withthe turbocharger 170 being at least partially spooled-up, the operatorthen releases the brake lever 88 to allow the snowmobile 10 toaccelerate (“launch”). In response to detecting the braking system 89being released, the controller 150 returns the engine to the standardcontrol strategy, removing all engine speed and torque limiting. As isillustrated in the example operation graph 290 of FIG. 6 , launchcontrol is released when the brake is released, where the ignition anglereverts back to the optimal ignition angle (approximately 25 degrees),all cylinders are all fully activated, and the accelerator position ismaintained. Having prepared the engine 26 and the turbocharger 170, theengine speed climbs relatively rapidly, from about 3200 RPM to about8000 RPM over a time frame of about one-half (0.5) second. Incomparison, a simulated engine speed curve (in broken line) shows that asimilar acceleration (from about 3200 RPM to 8000 RPM) without using thelaunch control mode of the present description would take about 1.5seconds. It should be noted that the illustrated simulation is simplyone non-limiting example and the exact acceleration time depends on theparticular vehicle embodiment.

If at any point, while the launch control mode is activated (fromoperation 230 to just prior to the brake lever 88 being released), thecontroller 150 determines that one or more deactivation conditions havebeen met, the controller 150 deactivates the launch control mode andreturns the snowmobile 10 to standard operations (see step 292 of themethod 300 as described below).

The controller 150 deactivates the launch control mode and returns thesnowmobile 10 to standard operations upon detection of one or more ofthe following deactivation conditions. Deactivation of the launchcontrol mode could occur upon detection of one or more of: thesnowmobile 10 not being in a forward gear; the engine 26 not running;the snowmobile 10 not being in sport mode; the snowmobile 10 having aspeed of greater than 0 km/h (0 mph), i.e. the snowmobile 10 not beingat rest; the temperature of the engine 26 exceeding mode-acceptableengine temperature limits; and detection of an unacceptable fault. It iscontemplated that in different embodiments the controller 150 mayconsider only some of these, or additional or alternative conditions.

The deactivation conditions further include time limits on some of theoperations described above to aid in preventing the engine 26 fromoverheating. As is illustrated in FIG. 5 , if the braking system 89 hasnot been activated within 30 seconds of activating the launch controlmode and increasing the engine speed to about 1800 RPM at operation 230,the controller 150 deactivates, at step 292, the launch control mode andreturns the snowmobile 10 and the engine 26 to standard operatingconditions. If the accelerator position has not been increased past 0%within 20 seconds after increasing the engine speed to about 3200 RPM atoperation 240, the controller 150 returns the engine 26 to normal idleand removes any torque limiting parameters that may have been activated.Similarly, if the braking system 89 have not been deactivated within 10seconds after opening the throttle valve 39 at operation 250, thecontroller 150 returns the engine 26 to normal idle and removes anytorque limiting parameters that may have been activated. When thebraking system 89 has been deactivated anew, the snowmobile 10 thenaccelerates and is operated according to the standard control strategy,i.e. the standard operating conditions.

In reference to FIG. 7 , a non-limiting embodiment of controlling theengine 26 and the snowmobile 10, according to the operations describedabove, is set out in the form of a method 300 performed by thecontroller 150. In some embodiments, it is contemplated that anadditional or substitute computer-implemented system could be used toperform the method 300.

The method 300 begins at step 310, with controlling, by the controller150, the engine 26 according to the standard control strategy. As ismentioned above, the standard control strategy manages the engine 26according to standard operational parameters, such as when thesnowmobile 10 is being operated according to typical procedures (e.g.being driven) and the engine 26 is not being controlled according to themethod 300.

The method 300 then continues, at step 320, with receiving, by thecontroller 150, a mode indication indicating that the operator of thesnowmobile 10 has selected the launch control mode for accelerating thesnowmobile 10 from rest. As is described above, the mode indication isreceived at the controller 150 from the mode input button 184, where theoperator selects the launch control mode is made available by thecontroller 150. In response to receiving the mode indication, thecontroller 150 activates the launch control mode and continues with themethod 300.

In at least some non-limiting embodiments, the controller 150 coulddetermine, prior to receiving the mode indication, that one or moreinitial mode conditions have been met. As is described above, theinitial mode conditions, also referred to as activation conditions,could include a variety of parameters, including but not limited to: thesnowmobile 10 being at rest, the temperature of the engine 26 beingwithin minimum and maximum limits, etc. A more complete non-limitinglist of possible initial mode conditions is set out above. In such anembodiment, in response to the initial mode conditions being met, thecontroller 150 could enable the mode input 184.

In some embodiments, in response to receiving the mode indication andprior to controlling the engine 26 according to subsequent steps of themethod 300, the controller 150 causes the engine 26 to increase enginespeed. As is mentioned above, this increased idle serves as an auditorysignal to the operator that the launch control mode has been activated.It is contemplated that the idle may not be increased in at least someembodiments.

The method 300 then continues, at step 330, with receiving, by thecontroller 150, a brake-on indication indicating that the braking system89 has been activated.

The method 300 then continues, at step 340, in response to receiving themode indication and the brake-on indication, with controlling the engine26 according to a launch control strategy. As is described above, thecontroller 150 causes the engine 26 to increase engine speed when boththe launch control mode is selected and the braking system 89 isactivated. Controlling the engine 26 according to the launch controlstrategy includes increasing the speed of the engine 26, and limitingthe torque output of the engine 26 if required. If the increased speedof the engine 26 does not approach the CVT engagement speed, at someinstances while controlling the engine 26 according to the launchcontrol mode it may not be necessary to limit torque output. As isdescribed above, controlling operational conditions of the engine 26 tolimit engine torque output includes delaying combustion ignition byadjusting the ignition timing and/or deactivating one or more cylinders.It is contemplated that alternative or additional approaches could beused to limit torque output of the engine 26.

The method 300 then continues, at step 350, while controlling the engine26 according to the launch control strategy, with determining anaccelerator position of the accelerator 86. When the acceleratorposition is at 0%, the operator has not moved the lever 86; when theaccelerator positions is greater than 0%, the operator has moved thelever 86 to request engine power.

The method 300 then continues, at step 360, in response to theaccelerator position being greater than zero percent, with controllingthe engine 26 to increase, according to the accelerator position, anopening of the throttle valve 39 and control operational conditions ofthe engine 39 to limit engine torque output. As is described above, airflow increases through the engine 26 in response to increasing theopening of the throttle valve 39 according to the accelerator position.

In some embodiments, subsequent to receiving the mode indication andprior to receiving a brake-off indication, the controller 150 coulddetermine that at least one deactivation condition has been met. Inresponse to one or more deactivation conditions being met, the method300 could then include returning to the standard operation mode wherebythe snowmobile 10 is operated according to the standard controlstrategy.

In some embodiments, while controlling the engine 26 according to thelaunch control strategy, the controller 150 could determine that one ormore of the deactivation conditions have been met. The method 300 couldthen further include returning to a standard operation mode whereby thesnowmobile 10 is operated according to the standard control strategy.

The method 300 then continues, at step 370, while controlling the engine26 according to the second control strategy, receiving a brake-offindication indicating that the braking system 89 has been released.

The method 300 then terminates, at step 380, in response to receivingthe brake off indication, with once again controlling the engine 26according to the standard control strategy. As the braking system hasbeen released at this point, the snowmobile 10 accelerates from rest perstandard operational parameters. Specifically, any torque output orengine speed limiting process applied to the engine 26 (such ascombustion delay and/or cylinder deactivation) is removed to allow theengine 26 to speed up and produce torque according to the position ofthe accelerator lever 86.

As is described above, the rate of acceleration from rest is greaterafter sequentially controlling the engine 26 according to the launchcontrol strategy (prior to controlling standard control strategy) than arate of acceleration from rest of the snowmobile 10 for correspondingchanges in accelerator position when controlling the engine 26 accordingto the standard control strategy without previously controlling theengine 26 according to the launch control strategy. This is due, atleast in part, to the spooling-up of the turbocharger 170 providedduring control of the engine 26 according to the launch controlstrategy. In response to controlling the engine 26 according to thelaunch control strategy then the standard control strategy in the method300, a speed of rotation of the turbocharger 170 increases.Specifically, the speed of rotation of the turbocharger 170 uponacceleration from rest is greater, when controlling the engine 26according to the launch then standard control strategies, than the speedof rotation of the turbocharger 170 upon acceleration from rest whencontrolling the engine 26 according to the standard control strategywithout previously controlling the engine 26 according to the launchcontrol strategy.

At any point during operation of the method 300, subsequent to receivingthe mode indication, the controller 150 could determine that one or moredeactivation conditions have been met. As is described above, the launchcontrol mode may need to be deactivated following detection of at leastone deactivation condition for a variety of reasons. One non-limitingexample of a deactivation condition is a time limit on operating theengine 26 at an increased engine speed, which is implemented at least inpart to aid in avoiding overheating of the engine 26. In some cases, thecontroller 150 could return the snowmobile 10 and the engine 26 to astandard operation mode, at step 292, whereby the snowmobile 10 isoperated according to the standard control strategy in response to atleast one deactivation condition being met. If, during operation of themethod 300, a time limit is exceeded after limiting the engine speed toabout 3200 RPM at step 360, the controller 150 could also return, atstep 294, the engine 26 to normal idle and removes any torque limitingparameters that may have been activated. In such a case, the method 300would then progress to step 292 to return the snowmobile 10 to standardoperation.

It is contemplated that the method 300 could include additional ordifferent steps, either to perform additional functions and/or toperform the steps described above.

The flowchart 200 and the method 300 could, in some non-limitingembodiments, be implemented by an all-terrain vehicle (ATV) 400, mutatismutandis. The ATV 400 will be described briefly with reference to FIGS.8 and 9 .

The ATV 400 has a frame 422 having a front end 424 and a rear end 426defined consistently with a forward travel direction of the ATV 400. TheATV 400 has two front wheels 430 and two rear wheels 430. Each of thefour wheels 430 is provided with low-pressure balloon tires adapted foroff-road conditions and traversing rugged terrain. It is contemplatedthat the ATV 400 could have six wheels 430 or only three wheels 430.

The two front wheels 430 are suspended from the frame 422 by left andright front suspension assemblies 432 while the two rear wheels 430 aresuspended from the frame 422 by left and right rear suspensionassemblies 434. The ATV 400 further includes a straddle seat 440connected to the frame 422 for accommodating a driver of the ATV 400.

An internal combustion engine 460 (schematically illustrated in FIG. 8 )is connected to the frame 422 for powering the ATV 400. The engine 460is disposed under the straddle seat 440. The wheels 430 are operativelyconnected to the engine 460. Driver footrests 442 are provided on eitherside of the straddle seat 440 and are disposed vertically lower than thestraddle seat 440 to support the driver's feet. The footrests 442 areconnected to the frame 422. A steering assembly 444 is rotationallyconnected the frame 422 to enable a driver to steer the ATV 400. Thesteering assembly 444 includes a handlebar 446 connected to a steeringcolumn assembly (not shown) for actuating steering linkages (not shown)operatively connected to left and right front wheels 430.

An accelerator lever 450, also referred to as an accelerator 450 or athrottle operator 450, in the form of a thumb-actuated throttle lever,is mounted to the handlebar 446. Other types of throttle operators, suchas a finger-actuated throttle lever and a twist grip, are alsocontemplated. A brake actuator 488, in the form of a hand brake lever488, is provided on the left side of the handlebar 446 for controlling abraking system 489 of the ATV 400 (shown schematically in FIG. 8 ).

A gear shifter 452 located near the handlebar 446 operates atransmission assembly (not shown) and enables the driver to select oneof a plurality of gear configurations for operation of the ATV 400. Inthe illustrated embodiment of the ATV 400, the gear configurationsinclude park, neutral, reverse, low, and drive. It is contemplated thatthe sequence and/or number of gear configurations could be differentthan as shown herein. A driving mode selector button 453 also enablesthe driver to select 2×4, 4×4, or sport mode operation of the ATV 400,as well the launch control mode as described above with respect to thesnowmobile 10. A display cluster 454, including a number of gauges andbuttons, is disposed forwardly of the steering assembly 444.

The ATV 400 further includes a controller (not shown) configured toperform a number of operations including methods described above foraccelerating the ATV 400 from rest using the launch control mode.

The controller of the ATV 400 is operatively and communicativelyconnected to various sensors and systems in order to perform the method300 (mutatis mutandis) including, but not limited to, at least one of:an ECU connected to the engine 460, the brake lever 488, the acceleratorlever 446, an intake air temperature sensor (not shown), the drivingmode selector button 453, an engine speed sensor (not shown), and anengine temperature sensor (not shown). For the ATV 400, the controlleris further communicatively connected to the gear shifter 452 (connectedto a gear shifter sensor, for example) in order to determine that theATV 400 is in a drive gear before enabling the launch control modeselection capability.

The ATV 400 further includes other components such as a radiator,headlights, and the like. As it is believed that these components wouldbe readily recognized by one of ordinary skill in the art, furtherexplanation and description of these components will not be providedherein.

The snowmobile 10, the ATV 400, and the method 300 implemented inaccordance with some non-limiting embodiments of the present technologycan be represented as follows, presented in numbered clauses.

CLAUSE 1. A method (300) for accelerating a vehicle (10, 400) from rest,the method (300) comprising: controlling, by a controller (150), anengine (26) of the vehicle (10, 400) according to a first controlstrategy; receiving, by the controller (150), a mode indicationindicating that an operator of the vehicle (10, 400) has selected alaunch control mode for accelerating the vehicle (10, 400); receiving,by the controller (150), a brake-on indication indicating that a brakingsystem of the vehicle (10, 400) has been activated; in response toreceiving the mode indication and the brake-on indication, controllingthe engine (26), by the controller (150), according to a second controlstrategy; while controlling the engine (26) according to the secondcontrol strategy, determining, by the controller (150), an acceleratorposition of an accelerator of the vehicle (10, 400); in response to theaccelerator position being greater than zero, controlling, by thecontroller (150), the engine (26) to: increase, according to theaccelerator position, an opening of a throttle valve of the engine (26),and control operational conditions of the engine (26) to limit enginetorque output; while controlling the engine (26) according to the secondcontrol strategy, receiving, by the controller (150), a brake-offindication indicating that the braking system has been released; and inresponse to receiving the brake-off indication, controlling the engine(26), by the controller (150), according to the first control strategy,controlling the engine (26) according to the first control strategy withthe braking system having been released causing the vehicle (10, 400) toaccelerate from rest, a first rate of acceleration from rest of thevehicle (10, 400) being greater than a second rate of acceleration fromrest of the vehicle (10, 400) for corresponding changes in acceleratorposition, the first rate of acceleration corresponding to the vehicle(10, 400) accelerating from rest after sequentially controlling theengine (26) according to the first and second control strategies; thesecond rate of acceleration corresponding to the vehicle (10, 400)accelerating from rest by controlling the engine (26) according to thefirst control strategy without previously controlling the engine (26)according to the second control strategy.

CLAUSE 2. The method (300) of clause 1, wherein, controlling the engine(26) according to the second control strategy includes: increasing aspeed of the engine (26), and limiting a torque output of the engine(26).

CLAUSE 3. The method (300) of clause 1 or 2, wherein controlling theengine (26) according to the first control strategy comprisescontrolling a turbocharged engine (26) of the vehicle (10, 400)according to standard operational parameters.

CLAUSE 4. The method (300) of any one of clauses 1 to 3, furthercomprising: prior to receiving the mode indication, determining, by thecontroller (150), that each of a plurality of initial mode conditionshave been met; and in response to the plurality of initial modeconditions being met, enabling a mode input by the controller (150), themode indication being sent to the controller (150) from the mode inputupon selection of the launch mode by the operator via the mode input.

CLAUSE 5. The method (300) of any one of clauses 1 to 4, furthercomprising, while controlling the engine (26) according to the secondcontrol strategy: determining, by the controller (150), that at leastone deactivation condition has been met; and in response to the at leastone deactivation condition being met, returning to a standard operationmode whereby the vehicle (10, 400) is operated according to the firstcontrol strategy.

CLAUSE 6. The method (300) of clause 5, wherein determining that the atleast one deactivation condition has been met includes determining thata time limit of controlling the engine (26) according to the secondcontrol strategy has been reached.

CLAUSE 7. The method (300) of any one of clauses 1 to 6, furthercomprising, subsequent to receiving the mode indication and prior toreceiving the brake-off indication: determining, by the controller(150), that at least one deactivation condition has been met; and inresponse to the at least one deactivation condition being met, returningto a standard operation mode whereby the vehicle (10, 400) is operatedaccording to the first control strategy.

CLAUSE 8. The method (300) of any one of clauses 1 to 7, whereincontrolling operational conditions of the engine (26) to limit enginetorque output comprises at least one of delaying combustion ignition;and deactivating at least one cylinder.

CLAUSE 9. The method (300) of any one of clauses 1 to 8, wherein inresponse to increasing the opening of the throttle valve according tothe accelerator position, air flow increases through the engine (26).

CLAUSE 10. The method (300) of any one of clauses 1 to 9, wherein, inresponse to controlling the engine (26) according to the first andsecond control strategies, a speed of rotation of a turbocharger of thevehicle (10, 400) increases.

CLAUSE 11. The method (300) of any one of clauses 1 to 10, wherein, afirst speed of rotation of a turbocharger of the vehicle (10, 400) uponacceleration from rest is greater than a second speed of rotation of theturbocharger upon acceleration from rest; the first speed of rotationcorresponds to the vehicle (10, 400) accelerating from rest aftersequentially controlling the engine (26) according to the first andsecond control strategies; and the second speed of rotation correspondsto the vehicle (10, 400) accelerating from rest by controlling theengine (26) according to the first control strategy without previouslycontrolling the engine (26) according to the second control strategy.

CLAUSE 12. The method (300) of any one of clauses 1 to 11, wherein, inresponse to receiving the mode indication and prior to controlling theengine (26) according to the second strategy, controlling the engine(26) to increase engine speed.

CLAUSE 13. The method (300) of clause 12, further comprising, subsequentto receiving the mode indication and prior to controlling the engine(26) according to the first strategy subsequent to receiving the modeindication: determining, by the controller (150), that at least onedeactivation condition has been met; and in response to the at least onedeactivation condition being met, returning to a standard operation modewhereby the vehicle (10, 400) is operated according to the first controlstrategy.

CLAUSE 14. The method (300) of clause 13, wherein determining that theat least one deactivation condition has been met includes determiningthat a time limit of increased engine speed has been reached.

CLAUSE 15. The method of clause 1, further comprising: determining, bythe controller, that a speed of the engine has surpassed a thresholdengine speed; and wherein the controller controls the engine accordingto the second control strategy in response to receiving the modeindication and the brake-on indication, and determining that the enginespeed has surpassed a threshold engine speed.

CLAUSE 16. A vehicle (10, 400) comprising: a frame; at least one seatconnected to the frame; an engine (26) supported by the frame; aturbocharger operatively connected to the engine (26); a controller(150) communicatively connected to the engine (26); and an acceleratorcommunicatively connected to the controller (150), the controller (150)being configured to perform the method (300) of any one of the clauses 1to 15.

CLAUSE 17. A vehicle (10, 400) comprising: a frame; at least two groundengaging members connected to the frame; a braking system operativelyconnected to at least one of the at least two ground engaging members;at least one seat connected to the frame; an engine (26) supported bythe frame; a turbocharger operatively connected to the engine (26); acontroller (150) communicatively connected to the engine (26); and anaccelerator communicatively connected to the controller (150), thecontroller (150) being configured to perform the steps of: controlling,by a controller (150), an engine (26) of the vehicle (10, 400) accordingto a first control strategy; receiving, by the controller (150), a modeindication indicating that an operator of the vehicle (10, 400) hasselected a launch mode for accelerating the vehicle (10, 400);receiving, by the controller (150), a brake-on indication indicatingthat a braking system of the vehicle (10, 400) has been activated; inresponse to receiving the mode indication and the brake-on indication,controlling the engine (26), by the controller (150), according to asecond control strategy; while controlling the engine (26) according tothe second control strategy, determining, by the controller (150), anaccelerator position of an accelerator of the vehicle (10, 400); inresponse to the accelerator position being greater than zero,controlling, by the controller (150), the engine (26) to: increase,according to the accelerator position, an opening of a throttle valve ofthe engine (26), and control operational conditions of the engine (26)to limit engine torque output; while controlling the engine (26)according to the second control strategy, receiving, by the controller(150), a brake-off indication indicating that the braking system hasbeen released; and in response to receiving the brake-off indication,controlling the engine (26), by the controller (150), according to thefirst control strategy, controlling the engine (26) according to thefirst control strategy with the braking system having been releasedcausing the vehicle (10, 400) to accelerate from rest, a first rate ofacceleration from rest of the vehicle (10, 400) being greater than asecond rate of acceleration from rest of the vehicle (10, 400) forcorresponding changes in accelerator position, the first rate ofacceleration corresponding to the vehicle (10, 400) accelerating fromrest after sequentially controlling the engine (26) according to thefirst and second control strategies; the second rate of accelerationcorresponding to the vehicle (10, 400) accelerating from rest bycontrolling the engine (26) according to the first control strategywithout previously controlling the engine (26) according to the secondcontrol strategy.

CLAUSE 18. The vehicle (10, 400) of clause 17, further comprising: amode input communicatively connected to the controller (150); andwherein the controller (150) is further configured to perform the stepsof: prior to receiving the mode indication, determining, by thecontroller (150), that each of a plurality of initial mode conditionshave been met, and in response to the plurality of initial modeconditions being met, enabling the mode input by the controller (150) toallow the operator to select the launch mode.

CLAUSE 19. The vehicle (10, 400) of clause 17 or 18, wherein: thevehicle (10) is a snowmobile (10); the at least two ground engagingelements include: two skis connected to the frame, and an endless trackdisposed rearward of the two skis; the at least one seat is at least onestraddle-seat; and the accelerator is an accelerator lever.

CLAUSE 20. The vehicle (10, 400) of any one of clauses 17 to 19,wherein: the vehicle (400) is an all-terrain vehicle (400) (ATV); the atleast two ground engaging elements include at least two wheels; the atleast one seat is at least one straddle-seat; and the accelerator is anaccelerator lever.

CLAUSE 21. A method (300) for accelerating a vehicle (10, 400) fromrest, the method (300) comprising: controlling, by a controller (150),an engine (26) of the vehicle (10, 400), the engine (26) having a firstmode and a second mode: the first mode controlling the engine speed froma first idle speed to a first maximum engine speed with respect to acorresponding idle accelerator position and a maximum acceleratorposition; the second mode controlling the engine speed from a secondidle speed to a second maximum engine speed with respect to thecorresponding idle acceleration position and the maximum accelerationposition, the second maximum engine speed being less than the firstmaximum engine speed, receiving, by the controller (150), a modeindication indicating that an operator of the vehicle (10, 400) hasselected a launch mode for accelerating the vehicle (10, 400);receiving, by the controller (150), a brake-on indication indicatingthat a braking system of the vehicle (10, 400) has been activated; inresponse to receiving the mode indication and the brake-on indication,controlling the engine (26), by the controller (150), according to thesecond mode; while controlling the engine (26) according to the secondmode, receiving, by the controller (150), a brake-off indicationindicating that the braking system has been released; and in response toreceiving the brake-off indication, controlling the engine (26), by thecontroller (150), according to the first mode, controlling the engine(26) according to the first mode with the braking system having beenreleased causing the vehicle (10, 400) to accelerate from rest.

Modifications and improvements to the above-described embodiments of thepresent technology may become apparent to those skilled in the art. Theforegoing description is intended to be exemplary rather than limiting.The scope of the present technology is therefore intended to be limitedsolely by the scope of the appended claims.

What is claimed is:
 1. A method for accelerating a vehicle from rest,the method comprising: controlling, by a controller, an engine of thevehicle according to a first control strategy; receiving, by thecontroller, a mode indication indicating that an operator of the vehiclehas selected a launch control mode for accelerating the vehicle;receiving, by the controller, a brake-on indication indicating that abraking system of the vehicle has been activated; in response toreceiving at least the mode indication and the brake-on indication,controlling the engine, by the controller, according to a second controlstrategy; while controlling the engine according to the second controlstrategy, determining, by the controller, an accelerator position of anaccelerator of the vehicle; in response to the accelerator positionbeing greater than zero, controlling, by the controller, the engine to:increase, according to the accelerator position, an opening of athrottle valve of the engine, and control operational conditions of theengine to limit engine torque output; while controlling the engineaccording to the second control strategy, receiving, by the controller,a brake-off indication indicating that the braking system has beenreleased; and in response to receiving the brake-off indication,controlling the engine, by the controller, according to the firstcontrol strategy, controlling the engine according to the first controlstrategy with the braking system having been released causing thevehicle to accelerate from rest, a first rate of acceleration from restof the vehicle being greater than a second rate of acceleration fromrest of the vehicle for corresponding changes in accelerator position,the first rate of acceleration corresponding to the vehicle acceleratingfrom rest after sequentially controlling the engine according to thefirst and second control strategies; the second rate of accelerationcorresponding to the vehicle accelerating from rest by controlling theengine according to the first control strategy without previouslycontrolling the engine according to the second control strategy.
 2. Themethod of claim 1, wherein, controlling the engine according to thesecond control strategy includes: increasing a speed of the engine, andlimiting a torque output of the engine.
 3. The method of claim 1,wherein controlling the engine according to the first control strategycomprises controlling a turbocharged engine of the vehicle according tostandard operational parameters.
 4. The method of claim 1, furthercomprising: prior to receiving the mode indication, determining, by thecontroller, that each of a plurality of initial mode conditions havebeen met; and in response to the plurality of initial mode conditionsbeing met, enabling a mode input by the controller, the mode indicationbeing sent to the controller from the mode input upon selection of thelaunch mode by the operator via the mode input.
 5. The method of claim1, further comprising, while controlling the engine according to thesecond control strategy: determining, by the controller, that at leastone deactivation condition has been met; and in response to the at leastone deactivation condition being met, returning to a standard operationmode whereby the vehicle is operated according to the first controlstrategy.
 6. The method of claim 5, wherein determining that the atleast one deactivation condition has been met includes determining thata time limit of controlling the engine according to the second controlstrategy has been reached.
 7. The method of claim 1, further comprising,subsequent to receiving the mode indication and prior to receiving thebrake-off indication: determining, by the controller, that at least onedeactivation condition has been met; and in response to the at least onedeactivation condition being met, returning to a standard operation modewhereby the vehicle is operated according to the first control strategy.8. The method of claim 1, wherein controlling operational conditions ofthe engine to limit engine torque output comprises at least one of:delaying combustion ignition; and deactivating at least one cylinder. 9.The method of claim 1, wherein in response to increasing the opening ofthe throttle valve according to the accelerator position, air flowincreases through the engine.
 10. The method of claim 1, wherein, inresponse to controlling the engine according to the first and secondcontrol strategies, a speed of rotation of a turbocharger of the vehicleincreases.
 11. The method of claim 1, wherein, a first speed of rotationof a turbocharger of the vehicle upon acceleration from rest is greaterthan a second speed of rotation of the turbocharger upon accelerationfrom rest; the first speed of rotation corresponds to the vehicleaccelerating from rest after sequentially controlling the engineaccording to the first and second control strategies; and the secondspeed of rotation corresponds to the vehicle accelerating from rest bycontrolling the engine according to the first control strategy withoutpreviously controlling the engine according to the second controlstrategy.
 12. The method of claim 1, wherein, in response to receivingthe mode indication and prior to controlling the engine according to thesecond strategy, controlling the engine to increase engine speed. 13.The method of claim 12, further comprising, subsequent to receiving themode indication and prior to controlling the engine according to thefirst strategy subsequent to receiving the mode indication: determining,by the controller, that at least one deactivation condition has beenmet; and in response to the at least one deactivation condition beingmet, returning to a standard operation mode whereby the vehicle isoperated according to the first control strategy.
 14. The method ofclaim 13, wherein determining that the at least one deactivationcondition has been met includes determining that a time limit ofincreased engine speed has been reached.
 15. The method of claim 1,further comprising: determining, by the controller, that a speed of theengine has surpassed a threshold engine speed; and wherein thecontroller controls the engine according to the second control strategyin response to receiving the mode indication and the brake-onindication, and determining that the engine speed has surpassed athreshold engine speed.
 16. A vehicle comprising: a frame; at least oneseat connected to the frame; an engine supported by the frame; aturbocharger operatively connected to the engine; a controllercommunicatively connected to the engine; and an acceleratorcommunicatively connected to the controller, the controller beingconfigured to perform the method of claim
 1. 17. A vehicle comprising: aframe; at least one two ground engaging members connected to the frame;a braking system operatively connected to at least one of the at leasttwo ground engaging members; at least seat connected to the frame; anengine supported by the frame; a turbocharger operatively connected tothe engine; a controller communicatively connected to the engine; and anaccelerator communicatively connected to the controller, the controllerbeing configured to perform the steps of: controlling, by a controller,an engine of the vehicle according to a first control strategy;receiving, by the controller, a mode indication indicating that anoperator of the vehicle has selected a launch mode for accelerating thevehicle; receiving, by the controller, a brake-on indication indicatingthat a braking system of the vehicle has been activated; in response toreceiving the mode indication and the brake-on indication, controllingthe engine, by the controller, according to a second control strategy;while controlling the engine according to the second control strategy,determining, by the controller, an accelerator position of anaccelerator of the vehicle; in response to the accelerator positionbeing greater than zero, controlling, by the controller, the engine to:increase, according to the accelerator position, an opening of athrottle valve of the engine, and control operational conditions of theengine to limit engine torque output; while controlling the engineaccording to the second control strategy, receiving, by the controller,a brake-off indication indicating that the braking system has beenreleased; and in response to receiving the brake-off indication,controlling the engine, by the controller, according to the firstcontrol strategy, controlling the engine according to the first controlstrategy with the braking system having been released causing thevehicle to accelerate from rest, a first rate of acceleration from restof the vehicle being greater than a second rate of acceleration fromrest of the vehicle for corresponding changes in accelerator position,the first rate of acceleration corresponding to the vehicle acceleratingfrom rest after sequentially controlling the engine according to thefirst and second control strategies; the second rate of accelerationcorresponding to the vehicle accelerating from rest by controlling theengine according to the first control strategy without previouslycontrolling the engine according to the second control strategy.
 18. Thevehicle of claim 17, further comprising: a mode input communicativelyconnected to the controller; and wherein the controller is furtherconfigured to perform the steps of: prior to receiving the modeindication, determining, by the controller, that each of a plurality ofinitial mode conditions have been met, and in response to the pluralityof initial mode conditions being met, enabling the mode input by thecontroller to allow the operator to select the launch mode.
 19. Thevehicle of claim 17, wherein: the vehicle is a snowmobile; the at leasttwo ground engaging elements include: two skis connected to the frame,and an endless track disposed rearward of the two skis; the at least oneseat is at least one straddle-seat; and the accelerator is anaccelerator lever.
 20. The vehicle of claim 17, wherein: the vehicle isan all-terrain vehicle (ATV); the at least two ground engaging elementsinclude at least two wheels; the at least one seat is at least onestraddle-seat; and the accelerator is an accelerator lever.
 21. A methodfor accelerating a vehicle from rest, the method comprising:controlling, by a controller, an engine of the vehicle, the enginehaving a first mode and a second mode: the first mode controlling theengine speed from a first idle speed to a first maximum engine speedwith respect to a corresponding idle accelerator position and a maximumaccelerator position; the second mode controlling the engine speed froma second idle speed to a second maximum engine speed with respect to thecorresponding idle acceleration position and the maximum accelerationposition, the second maximum engine speed being less than the firstmaximum engine speed, receiving, by the controller, a mode indicationindicating that an operator of the vehicle has selected a launch modefor accelerating the vehicle; receiving, by the controller, a brake-onindication indicating that a braking system of the vehicle has beenactivated; in response to receiving the mode indication and the brake-onindication, controlling the engine, by the controller, according to thesecond mode; while controlling the engine according to the second mode,receiving, by the controller, a brake-off indication indicating that thebraking system has been released; and in response to receiving thebrake-off indication, controlling the engine, by the controller,according to the first mode, controlling the engine according to thefirst mode with the braking system having been released causing thevehicle to accelerate from rest.